Filtrate
Gloved hand holding translucent renal biopsy slide up to window light, tissue section glowing amber and pink against blurred clinical background
Clinical Reference
Feb 2026 · Vol. 12
Nephrology · KDIGO 2025

Every Condition. Every Pathway. One Library.

Peer-reviewed nephrology briefs organized by diagnosis, stage, and intervention.

Audit your clinical knowledge in under three minutes

Explore the Full Library
180+
Condition Briefs
64
Treatment Algorithms
KDIGO
Guideline Aligned
GFR StagingProteinuria GradingFSGS PathologyDialysis AdequacyCKD-MBD ProtocolTransplant RejectionTubular AcidosisNephrotic SyndromeHyperkalemia ManagementRRT InitiationMembranous NephropathyIgA NephropathyGFR StagingProteinuria GradingFSGS PathologyDialysis AdequacyCKD-MBD ProtocolTransplant RejectionTubular AcidosisNephrotic SyndromeHyperkalemia ManagementRRT InitiationMembranous NephropathyIgA Nephropathy
01
Glomerular Disease

Can you stage the proteinuria, then choose the biopsy threshold?

Glomerular disease spans nephrotic to nephritic presentations. Filtrate organizes IgA nephropathy, FSGS, membranous nephropathy, and ANCA vasculitis by Oxford/ISN classification with linked immunosuppression protocols.

Clinical Self-Audit
What urine ACR threshold triggers renal biopsy in a 42-year-old with microscopic hematuria?
Which FSGS variant (tip lesion vs. perihilar) predicts steroid responsiveness and by how much?
At what serum albumin level do you initiate VTE prophylaxis in nephrotic syndrome?
What Oxford MEST-C score drives immunosuppression in IgA nephropathy with eGFR > 30?
When does membranous nephropathy PLA2R titer guide rituximab re-dosing vs. watchful waiting?
See All Glomerular Briefs
Treatment Algorithm

FSGS — First-Line Protocol

KDIGO 2021 · Steroid-Sensitive Pathway

Confirm Diagnosis
Biopsy: FSGS on LM + EM foot process effacement > 80%
Initiate Therapy
Prednisone 1 mg/kg/day (max 80 mg) × 16 weeks
Response Assessment
Complete remission: proteinuria < 300 mg/day by week 16
Steroid-Resistant
Cyclosporine 3–5 mg/kg/day OR tacrolimus 0.1 mg/kg/day
Monitor
eGFR, BP < 125/75, trough CsA 100–175 ng/mL q4 weeks

Adjust cyclosporine trough to 75–125 ng/mL if eGFR declines > 25% from baseline. Discontinue if no remission at 6 months.

02
Electrolyte & CKD-MBD

Do you have a protocol for phosphate binder selection at eGFR 22?

Mineral and bone disorder in CKD accelerates cardiovascular calcification silently. Filtrate maps the PTH–FGF23–Klotho axis with intervention thresholds calibrated to CKD stage 3b through dialysis.

Clinical Self-Audit
At what PTH level do you switch from calcium-based to non-calcium phosphate binder in CKD G4?
What is the target serum phosphate range in HD patients per KDIGO 2017, and how often do you reassess?
When does calcimimetic therapy (cinacalcet vs. etelcalcetide) outperform parathyroidectomy in SHPT?
What FGF23 trajectory in CKD G3b predicts rapid progression to ESRD within 24 months?
How do you dose active vitamin D analogs (calcitriol vs. paricalcitol) when PTH is 450 pg/mL?
Open Electrolyte Protocols
Treatment Algorithm

CKD-MBD — Phosphate Management

CKD Stage G3b–G5 · KDIGO 2017

Baseline Labs
Ca, PO4, PTH, 25-OH-D, ALP every 3–6 months (G3b–G4)
Phosphate Target
Serum PO4: 3.5–5.5 mg/dL (HD); < 4.6 mg/dL (pre-dialysis)
Binder Selection
Calcium carbonate 500 mg TID with meals (if Ca < 9.5 mg/dL)
Non-Calcium Binder
Sevelamer carbonate 800 mg TID if Ca ≥ 9.5 or PTH < 150 pg/mL
PTH Suppression
Target iPTH 2–9× upper limit of normal for CKD stage

Avoid calcium binders if coronary artery calcification score > 400 on CT. Reassess binder choice if corrected calcium rises above 10.2 mg/dL.

03
Transplant Complications

Can you distinguish TCMR from ABMR on the morning biopsy report?

Post-transplant nephrology demands rapid protocol decisions. Filtrate structures acute rejection phenotyping, CNI toxicity surveillance, BK nephropathy screening, and de novo DSA management into actionable decision trees.

Clinical Self-Audit
What Banff 2022 criteria distinguish T-cell mediated rejection (TCMR) Grade IIA from Grade IIB?
At what DSA MFI threshold do you initiate antibody-mediated rejection (ABMR) treatment?
When does BK viremia (> 10,000 copies/mL) mandate tacrolimus dose reduction vs. immunosuppression cessation?
What tacrolimus trough targets apply at 0–3 months vs. 12 months post-transplant?
How do you manage de novo anti-HLA DSA detected at 6-month surveillance with stable creatinine?
See All Transplant Protocols
Treatment Algorithm

Acute TCMR — Treatment Protocol

Banff 2022 · Grades I–III Pathway

Biopsy Confirmation
Banff Grade IA/IB: tubulitis t2/t3 + i1–i3 interstitial inflammation
First-Line Therapy
Methylprednisolone 500 mg IV × 3 days (pulse steroids)
Grade IIA–IIB
Pulse steroids + optimize CNI trough to 8–12 ng/mL (tacrolimus)
Steroid-Resistant
Thymoglobulin 1.5 mg/kg/day × 5–7 days (total 6–10 mg/kg)
Post-Treatment
Repeat biopsy at 6 weeks; DSA panel at 3 months post-episode

Grade III TCMR (vascular rejection v3) carries 40% graft loss at 1 year. Escalate to thymoglobulin regardless of steroid response.

Reference
The Full Reference

The handbook your attendings wished existed.

Every GFR threshold. Every immunosuppression taper. Every dialysis adequacy target — structured for the way nephrologists actually think.

Explore the Full Library
180+
Condition Briefs
From FSGS to ANCA vasculitis
64
Treatment Algorithms
Dosing thresholds, monitoring intervals
12
Disease Categories
Glomerular to transplant
KDIGO
Guideline Aligned
2025 CKD & AKI standards